Search results for "exchanger"

Phosphororganische Verbindungen. 60. Mitt. Aufbau und Eigenschaften eines optisch aktiven Anionenaustauschers mit identischem Chiralitäts- und Ladung…

1968

Chlormethyliertes Polystyrol (vernetzt mit 0,5% Divinylbenzol) wird mit (+)-Methyl- n-propyl-phenyl-phosphin quartarisiert. Der entstehende Austauscher besitzt eine Kapazitat von 2,68 mVal/g. Mandelsaure, Atrolactinsaure und Traubensaure konnten an diesem Material nicht in die Antipoden gespalten werden. Chlormethylated polystyrene (crosslinked with 0.5% divinylbenzene) is quaternized with (+)-methyl-n-propyl-phenyl-phosphine. The resultant anion exchanger has a capacity of 2.68 m.equiv./g. Mandelic acid, atrolactic, and rac. tartaric acid could not be resolved into the antipodes on this material.

Flow and Heat Transfer in Corrugated Passages: Direct and Large-Eddy Simulation and Comparison with Experimental Results

1993

Recovery of aliphatic low-molecular-mass carboxylic acids from hardwood kraft black liquor

2015

Abstract During alkaline pulping of wood, substantial amounts of carbohydrates-derived aliphatic carboxylic acids (formic and acetic acids together with various hydroxy acids) are formed and dissolved into the cooking liquor (“black liquor”). These acids with low heating values are considered to be potential feedstocks for the chemical industry but, due to many factors, their straightforward recovery as free acids from black liquor (pH 13–14) is difficult. In this paper, we outlined the partial recovery of volatile formic and acetic acids from the acidified birch ( Betula pendula ) kraft black liquor (pH approximately 2.5) by distillation, and the partial recovery of significant low-molecul…

Novel Instrument for Temperature Measurements in Borehole Heat Exchangers

2019

The thermal response test (TRT) is the standard method for characterizing the thermal properties of the ground and those of a borehole heat exchanger (BHE). During the TRT, the inlet and outlet temperatures of the BHE are monitored. However, this test typically considers the ground as a homogeneous, isotropic, and infinite media, and therefore, it only determines the bulk and effective parameters, such as effective thermal conductivity and thermal borehole resistance. Hence, the enhanced TRT protocols are necessary where the depth-dependent temperatures are measured to estimate depth-specific thermal properties. Thus, a novel instrument with a data logger to automatically obtain the tempera…

Thermal energy storage in granular deposits

2017

Energy storage technology is crucial for the development of the use of renewable energy sources. This is a substantial constraint, however it can, to some extent, be solved by storing energy in its various forms: electrical, mechanical, chemical and thermal. This article presents the results of research in thermal properties of granular deposits. Correlation between temperature changes in the stores over a period of time and their physical properties has been studied. The results of the research have practical application in designing thermal stores based on bulk materials and ground deposits. Furthermore, the research results are significant for regeneration of the lower ground sources for…

A minireview on NHE1 inhibitors. A rediscovered hope in oncohematology.

2015

Background: Na+/H+ exchanger-1 (NHE-1) is involved in pH regulation and is up-regulated in different malignancies. Activation of NHE-1 is one way for allowing cells to avoid intracellular acidification and protect them against apoptosis. Inhibitors of NHE-1 are able to decrease intracellular pH and induce apoptosis. Some statins can also act by partial inhibition of NHE-1. This review presents progress in understanding the mechanisms of action of these inhibitors, connections with certain genetic mutations and acquired treatment resistance, as well as new patents on them. Methods: A MEDLINE search for original and review articles using key terms, Na+/H+ exchanger, leukemia, cariporide, and …

Sodium-hydrogen exchange inhibition: novel strategy to prevent myocardial injury following ischemia and reperfusion.

1999

Activation of Na+/H+ exchange and subsequent calcium overload in cardiac myocytes appear to play an important role in myocardial tissue injury following ischemia and reperfusion. Results of several in vitro studies in isolated myocytes and heart preparations and in vivo studies in pigs and rats have suggested that inhibition of Na+/H+ exchange is an effective means to prevent lethal reperfusion injury, arrhythmia, and improve myocardial contractile dysfunction. In patients with acute myocardial infarction (MI), any preventive agent is administered immediately before or shortly after reperfusion, rather than before the occurrence of coronary occlusion. The direct interventional approach to t…

"Thermal penalty factors" accounting for site topological characteristics in pinch design of Heat Exchanger Networks

2010

Pinch analysis allows to determine targets and solutions for minimum energy requirements in process plants, basing on innovative tools like composite curves and table problem formulation, which ultimately allow generating an optimized heat exchanger network design. On another hand, this technique does not account directly for a number of factors which could play a primary role for the practical feasibility of the network. What if, for instance, once identified an optimal lay-out, we realize that some matches are hardly feasible in practice? Could we adapt the conventional pinch approach to keep into account site topological features since the preliminary design phase? In this paper the auth…

Tenapanor for the treatment of irritable bowel syndrome with constipation.

2020

Introduction: Irritable bowel syndrome with constipation is associated with higher rates of functional impairment, as compared to other subtypes of the syndrome. Conventional laxative-based pharmacologic therapy of IBS-C, which is mostly symptom-based, is often unsatisfactory. Tenapanor represents a first-in-class orally available inhibitor of NHE3, which is minimally absorbed in the GI tract, what constitutes a significant therapeutic benefit, as it may act on the drug target. Areas covered: Aim of this article is to sum up the evidences about pharmacodynamics and pharmacokinetics of tenapanor, focusing on animal models and in vitro studies, but also discuss clinical trials on tenapanor's …

Bilevel heat exchanger network synthesis with an interactive multi-objective optimization method

2012

Abstract Heat exchanger network synthesis (HENS) has been an active research area for more than 40 years because well-designed heat exchanger networks enable heat recovery in process industries in an energy- and cost-efficient manner. Due to ever increasing global competition and need to decrease the harmful effects done on the environment, there still is a continuous need to improve the heat exchanger networks and their synthesizing methods. In this work we present a HENS method that combines an interactive multi-objective optimization method with a simultaneous bilevel HENS method, where the bilevel part of the method is based on grouping of process streams and building aggregate streams …